Question

find the HCF and LCM of 12 , 15 , 21 by applying prime factorisation method​

Answer 1

Step-by-step explanation:

LCM of 12, 15 , 21 :

12 = 2×2×3

15 = 3×5

21 = 3×7

you are see that their have a common factor 3.

her HCF

3×2×2×5×7 [you see their have a only one 3 because this is a HCF of 12,15,21 ]

so we have a answer = 420